The invention relates to a device for heat transfer and in particular an evaporator in particular for air conditioning systems of motor vehicles having at least one header tank comprising at least two header chambers. Although the invention will be described below with reference to the evaporator of an air conditioning system of a motor vehicle, reference is made to that a limitation to such use is not intended but use in other air conditioners and the like is also included.
Such heat exchanger devices as mentioned above have been known in the prior art. DE 198 26 881 A1 discloses a heat exchanger having a header tank made of sheet metal formed from a pretreated plate. The header tank is divided into two chambers in the longitudinal direction wherein the ends of two rows of flat tubes arranged in-line are inserted into the base section or plate of the header tank through which the air to be cooled flows. The header chambers comprise side walls wherein the adjacent side walls of the two header chambers are in parallel and directly bordering each other and are brazed to one another and to the base to ensure tight sealing of the header tank.
DE 100 56 074 A1 discloses a heat exchanger where, contrary to other known devices, the connecting flanges are not mounted to the end faces of the header tank but to a longitudinal side such that a simple construction is achieved without additional components. In such a heat exchanger the adjacent side wall surfaces of the two chambers are also mounted in parallel and brazed to one another and to the header tank.
A drawback of the prior art heat exchangers is that manufacturing tolerances must be fairly narrow so as to minimize rejects.
It is therefore the object of the present invention to provide a heat exchanger which allows larger manufacturing tolerances.